Isomerism

This question is about the analysis of organic compounds.

Determine the R_f value of propan-1-ol.

Show your working.

Write an equation for the alkaline hydrolysis of 1-bromopropane.

Show structures of organic compounds.

A student investigates the alkaline hydrolysis of 1-chloropropane using the same method as for 1-bromopropane.

Predict, with reasons, how the appearance of the reaction mixture in the chromatogram produced after 20 minutes would be different when 1-chloropropane is used instead of 1-bromopropane.

Suggest why propan-1-ol is run alongside the reaction mixture.

Write the formula of the species causing the colours after refluxing with acidified dichromate(VI

Green solution........

Orange solution........

* The student is provided with further information about compounds F– I.

• They all have the molecular formula C₅H₁₀O.

• One of the compounds is alicyclic.

• The other compounds are unbranched.

Use this further information and the student’s observations in Table 5.1 to answer the following.

• How do the observations provide evidence for the possible functional groups in compounds F– I ?

• Suggest a possible structure for each of the compounds F– I.

Show your reasoning.

This question is about unsaturated hydrocarbons.

What is the systematic name of hydrocarbon A ?

Compounds B and C are branched hydrocarbons that are structural isomers of C₆H₁₂.

Compounds B and C both have stereoisomers.

• Compound B has cis and trans isomers but does not have optical isomers.

• Compound C has optical isomers but does not have cis and trans isomers.

What is meant by the term structural isomers ?

What is meant by the term stereoisomers ?

Draw structures for the cis and trans isomers of the branched hydrocarbon B.

Draw 3D structures for the optical isomers of compound C.

Compounds D and E are two more structural isomers of C₆H₁₂.

Compounds D and E do not show stereoisomerism.

Table 16.1 shows NMR and infrared (IR) spectral data for D and E.

Draw the structures of D and E and explain how the spectral data in Table 16.1 provides evidence for the structures.

Draw the structures of the products you would expect from the ozonolysis of the two compounds below.

2-Methylbutane is reacted with chlorine by radical substitution.

What is the number of structural isomers with the molecular formula C₅H₁₁Cl that could be formed?

A 2

B 3

C 4

D 5

What is the number of alicyclic structural isomers of C₅H₁₀?

A 3

B 4

C 5

D 6

This question is about unsaturated aldehydes and alcohols.

Outline the reaction mechanism for the formation of one of the organic products.

Include curly arrows and relevant dipoles.

Explain why one of the organic products forms in a much greater quantity than the other organic product.

Describe how the observations from a chemical test would distinguish between geraniol and citronellal.

What is the molecular formula of geraniol?

Explain why geraniol and citronellal are structural isomers of each other.

Explain the term stereoisomerism.

How many straight-chain structural isomers of C₇H₁₅Cl contain a chiral carbon atom?

A 1

B 2

C 3

D 4

Which compound(s) is a/are structural isomer(s) of C₆H₁₂O₂?

1 hexanoic acid

2 ethyl butanoate

3 propyl propanoate

A 1, 2 and 3

B Only 1 and 2

C Only 2 and 3

D Only 1